Sure you can just throw a plant in some soil and water it regularly and do nothing else. But when you're ready to advance your skill and your plant quality, nutrients are valuable tool.
When it comes to choosing your nutrients, there are only two options; liquid nutrients or dry nutrients. There's pros and cons to each, and as always, it'll come down to your situation and preference.
Liquid nutrients have become the standard for large scale cultivation, mainly for its ease of application on a large scale. With a reservoir system and irrigation a grower can easily dose out their liquid nutrients for regular, automated feedings.
Another benefit to liquid nutrients is that they are traditionally more concentrated than dry nutrients. Being a concentrated liquid mixed directly into water makes the nutrients more directly available to your plants, meaning they will start taking up nutrients faster compared to dry nutrients.
However because your plants take up nutrients faster, they typically require more feedings, and it can be easy to overfeed when you have to feed more often. Another common mistake made with liquid nutrients is not diluting the nutrient enough before application. The high concentrations of nutrients can overwhelm your plants, resulting in nutrient burn or nutrient lockout. Luckily these problems can be solved relatively easy if you catch them in time.
Dry nutrients are a popular option for growers that don't want to feed as often but still want to ensure their plants get all the essential nutrients they need. Typically a dry nutrient is applied in a powder or granular form as a top dress to your soil or medium.
After watering the nutrient into the medium, they are slowly absorbed by the plants over time. Not being as concentrated as liquid nutrients, dry nutrients take longer to absorb into your soil and roots, which is why growers that are trying to feed more often tend to avoid dry nutrients.
Basically the same reasons people like to use dry nutrients, are the same reasons others choose to avoid them. They work slower, and you can't feed your plants as often. For growers on a schedule, timing is everything, and some growers just don't want to wait for a dry nutrient to take effect when they could use a liquid nutrient and feed more often for bigger plants.
It all depends on your grow style! You can feed a lot of plants heavy at first with a dry nutrient and let them absorb the nutrients over time, or you can do the same, but a little more often with liquid nutrients.
But really, if you want consistency in an easy application, liquid nutrients are the way to go. As long as you follow the instructions and mix properly, you can fill up a full reservoir, set it and forget it. However dry nutrients have improved over the past few years, and if we had to recommend one brand you just have to try, it would be GeoFlora Veg and Bloom dry nutrient.
GeoFlora is an OMRI listed organic nutrient with 19 different organic inputs to provide your plants everything they need with only weekly feedings.